u ← 1 0j1 +.× ? 2 20⍴10

   x ← u[?1e4 3⍴≢u]
   y ← u[?1e4 3⍴≢u]

   hz ← {⍳⍨ ⍉cluster⍤1⍉ |⍵}

   (x⍳y) ≡ x hz HASH y
1

   cmpx 'x hz HASH y' 'x⍳y'
  x hz HASH y → 3.50E¯2 |     0% ⎕
  x⍳y         → 1.39E0  | +3875% ⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕⎕